1. Field of the Disclosure
The present disclosure relates to wireless communication systems, and more particularly to aligning wireless location area network operations with power headroom reporting over a wide area network.
2. Description of Related Art
Wireless communications systems are widely deployed to provide various types of communication content such as voice, video, packet data, messaging, broadcast, and so on. These systems may be multiple-access systems capable of supporting communication with multiple users by sharing the available system resources (e.g., time, frequency, and power). A wireless network, for example a Wireless Local Area Network (WLAN), such as a Wi-Fi network (IEEE 802.11) may include an access point (AP) that may communicate with stations (STAs) or mobile devices. The AP may be coupled to a network, such as the Internet, and enable a mobile device to communicate via the network (and/or communicate with other devices coupled to the access point). Other examples of such multiple-access systems include code-division multiple access (CDMA) systems, time-division multiple access (TDMA) systems, frequency-division multiple access (FDMA) systems, and orthogonal frequency-division multiple access (OFDMA) systems. The systems may include a base station communicating with mobile devices.
In conventional cellular communications systems, e.g., long term evolution (LTE) systems, a transmit power of a mobile device is normally controlled by the base station. However, there may be times when the mobile device independently reduces its transmit power and reports its modified transmit power limit to the base station so that the base station is aware of the reduced transmit power limit for the base station. Otherwise, the base station may assume, for example, that the mobile device can transmit with full power and schedule the mobile device to transmit with a wider bandwidth and/or using a modulation coding scheme (MCS) that requires full power. The mobile device may inform the base station of its power limit via a power headroom (PHR) report. Generally, the base station determines how often and at which instance the mobile device is allowed to transmit its PHR report.
One reason a mobile device may reduce its transmit power is to avoid interference between multiple radios on the mobile device. Multiple radios (e.g., an LTE radio and a WLAN radio) on the same mobile device can interfere with each other causing severely degraded performance. For example, LTE operations may interfere with WLAN scan/connection setup (such as association), data transmission and the like, and therefore negatively impact user experience. To help reduce such interference, the mobile device may reduce its LTE transmit power during WLAN operations. This may be referred to as transmit power backoff or reduction. Currently, transmit power backoff or reduction during WLAN operations is not aligned with mobile device PHR report transmissions.